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    <title>mfft</title>
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    <center>Scilab Function</center>
    <div align="right">Last update : April 1993</div>
    <p>
      <b>mfft</b> -  multi-dimensional fft</p>
    <h3>
      <font color="blue">Calling Sequence</font>
    </h3>
    <dl>
      <dd>
        <tt>[xk]=mfft(x,flag,dim)  </tt>
      </dd>
    </dl>
    <h3>
      <font color="blue">Parameters</font>
    </h3>
    <ul>
      <li>
        <tt>
          <b>x</b>
        </tt>: <tt>
          <b>x(i,j,k,...)</b>
        </tt> input signal in the form of a row vector whose values are arranged so that the i index runs the quickest, followed by the j index, etc.</li>
      <li>
        <tt>
          <b>flag</b>
        </tt>: (-1) FFT or (1) inverse FFT</li>
      <li>
        <tt>
          <b>dim</b>
        </tt>: dimension vector which gives the number of values of <tt>
          <b>x</b>
        </tt> for each of its indices</li>
      <li>
        <tt>
          <b>xk</b>
        </tt>: output of multidimensional fft in same format as for <tt>
          <b>x</b>
        </tt>
      </li>
    </ul>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>
    FFT for a multi-dimensional signal</p>
    <p>
    For example for a three dimensional vector which has three points
    along its first dimension, two points along its second
    dimension and three points along its third dimension the row
    vector is arranged as follows</p>
    <pre>

     x=[x(1,1,1),x(2,1,1),x(3,1,1),
        x(1,2,1),x(2,2,1),x(3,2,1),
              x(1,1,2),x(2,1,2),x(3,1,2),
              x(1,2,2),x(2,2,2),x(3,2,2),
                    x(1,1,3),x(2,1,3),x(3,1,3),
                    x(1,2,3),x(2,2,3),x(3,2,3)]
   
    </pre>
    <p>
    and the <tt>
        <b>dim</b>
      </tt> vector is: <tt>
        <b>dim=[3,2,3]</b>
      </tt>
    </p>
    <h3>
      <font color="blue">Author</font>
    </h3>
    <p>C. B.  </p>
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